GRB070531

Analysis Summary

Notes:

1) No attempt has been made to eliminate the non-significant decimal places.
2) This batgrbproduct analysis is done using the HEASARC data.
3) This batgrbproduct analysis is using the flight position for the mask-weighting calculation.

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Mon Jan 20 09:17:52 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger280958
======================================================================

  Trigger: 00280958      Segment: 000

  BAT Trigger Time: 202270219.52   [s; MET]
      Trigger Stop: 202270223.616   [s; MET]
               UTC: 2007-05-31T02:10:17.529860    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 6.67853589686105   Dec: 74.3038706234283  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    10.24
     Image Trigger?:     NO
     Rate S/N Ratio:     14.0712472794703  [ if not an image trigger ]
     Image S/N Ratio:    10.24

  Analysis Position:   [ source = BAT ]
    RA: 6.67853589686105   Dec: 74.3038706234283  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 6.70925035211524   Dec: 74.3091694426409  [deg; J2000]  
        { 00h 26m 50.2s , +74d 18' 33.0" }
         +/- 1.69722096771065 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.7001579311515 [arcmin] (formal 1-sigma fit error)
    SNR: 14.2863301482455
 
  Angular difference between the analysis and refined position is 0.591236 arcmin
 
  Partial Coding Fraction: 0.4414062    [ including projection effects ]

  Duration
     T90: 44.6200000047684 +/- 6.05522751926021
        Measured from: -1.04000002145767
                   to: 43.5799999833107     [s; relative to TRIGTIME]
     T50: 21.8920000195503 +/- 6.29776371782261
        Measured from: 2.55199998617172
                   to: 24.444000005722     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 1.0799999833107     
                   to: 2.0799999833107     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -2.41200000047684     
                   to: 46.3400000035763     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.302267   0.603663   0.504623   0.204601
           0.055350   0.058720   0.054126   0.052569 [error]
 Peak      0.018697   0.038333   0.049435   0.023505
           0.007876   0.008759   0.008355   0.007787 [error]

     [ fluence units of on-axis counts / fully illuminated detector ] 

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   48.752   -2.412   46.340
T90    44.620   -1.040   43.580
T50    21.892    2.552   24.444
Peak    1.000    1.080    2.080
 
 
====== Spectral Analysis Summary =====================================
 
Model      : spectral model: simple power-law (PL) and cutoff power-law (CPL)
Ph_index   : photon index: E^{Ph_index}
Ph_90err   : 90% error of the photon index
Epeak      : Epeak in keV
Epeak_90err: 90% error of Epeak
Norm       : normalization at 50 keV in both the PL model and CPL model
Nomr_90err : 90% error of the normalization
chi2       : Chi-Squared
dof        : degree of freedo
 
=== Time-averaged spectral analysis ===
(Best model with acceptable fit: PL)
 
Model Ph_index Ph_90err_low Ph_90err_hi  Epeak  Epeak_90err_low  Epeak_90err_hi  Norm       Nomr_90err_low    Norm_90err_hi    chi2    dof
PL      -1.320    -0.192      0.194       -           -               -         2.27e-03     -2.48e-04          2.48e-04      56.590   57
CPL     -1.075    -0.414      0.804      205.256    -205.256      -205.256      2.96e-03     -2.96e-03          3.90e-03      56.240   56
 
 
=== 1-s peak spectral analysis ===
(Best model with acceptable fit: PL)
 
Model Ph_index Ph_90err_low Ph_90err_hi  Epeak  Epeak_90err_low  Epeak_90err_hi  Norm       Nomr_90err_low    Norm_90err_hi    chi2    dof
PL      -0.875     -0.359     0.400       -           -               -         8.60e-03     -1.95e-03          1.87e-03      48.680   57
CPL     -0.756      N/A       N/A         661.796      N/A           N/A         9.60e-03        N/A               N/A         48.660   56
 
 
=== Fluence/Peak Flux Summary ===
 
              Model    Band1     Band2     Band3     Band4     Band5     Total
                       15-25     25-50    50-100    100-350    15-150    15-350    keV
Fluence         PL   1.19e-07  2.45e-07  3.92e-07  1.40e-06  1.09e-06  2.16e-06   erg/cm2
      90%_error_low -2.41e-08 -3.08e-08 -5.20e-08 -3.72e-07 -1.29e-07 -4.10e-07   erg/cm2
      90%_error_hi   2.56e-08  3.03e-08  5.14e-08  4.55e-07  1.30e-07  4.79e-07   erg/cm2
Peak flux       PL   1.95e-01  2.85e-01  3.11e-01  6.36e-01  9.87e-01  1.43e+00   ph/cm2/s
      90%_error_low -8.55e-02 -8.57e-02 -6.30e-02 -2.44e-01 -2.15e-01 -2.99e-01   ph/cm2/s
      90%_error_hi   1.03e-01  8.38e-02  6.27e-02  3.37e-01  2.18e-01  3.17e-01   ph/cm2/s
 
Fluence        CPL   1.13e-07  2.50e-07  4.02e-07  1.00e-06  1.07e-06  1.77e-06   erg/cm2
      90%_error_low -2.94e-08 -3.39e-08 -5.72e-08 -5.95e-07 -1.37e-07 -6.06e-07   erg/cm2
      90%_error_hi   2.54e-08  3.51e-08  5.98e-08  5.35e-07  1.36e-07  5.72e-07   erg/cm2
Peak flux      CPL   1.88e-01    N/A    3.16e-01  5.79e-01  9.82e-01  1.41e+00   ph/cm2/s
      90%_error_low -1.13e-01 -8.57e-02 -6.76e-02 -5.79e-01 -2.23e-01 -5.35e-01   ph/cm2/s
      90%_error_hi   8.25e-02  8.38e-02  8.63e-02  2.35e-01  2.13e-01  3.03e-01   ph/cm2/s
 
======================================================================

Special notes of this burst

Image

Pre-slew 15.0-350.0 keV image (Event data)

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
    6.7093    74.3092   0.0134    44.1503  -175.4577         1.6180363     14.286 TRIG_00280958                 
 
Foreground time interval of the image:
 -2.412  40.581 (delta_t =  42.993 [sec])
Background time interval of the image:
-239.520  -2.412 (delta_t = 237.108 [sec])

Light Curves

Note: The mask-weighted lightcurves have units of either count/det or counts/sec/det, where a det is 0.4 x 0.4 = 0.16 sq cm.

Full-time range; 1 s binning

Bokeh Plot

Other quick-look light curves:

64 ms binning (zoomed)
16 ms binning (zoomed)
8 ms binning (zoomed)
2 ms binning (zoomed)
SN=5 or 10 s binning (full-time range)
Raw light curve

Spectra

Notes:

1) The fitting includes the systematic errors.
2) When the burst includes telescope slew time periods, the fitting uses an average response file made from multiple 5-s response files through out the slew time plus single time preiod for the non-slew times, and weighted by the total counts in the corresponding time period using addrmf. An average response file is needed becuase a spectral fit using the pre-slew DRM will introduce some errors in both a spectral shape and a normalization if the PHA file contains a lot of the slew/post-slew time interval.
3) For fits to more complicated models (e.g. a power-law over a cutoff power-law), the BAT team has decided to require a chi-square improvement of more than 6 for each extra dof.

Time averaged spectrum fit using the average DRM

Power-law model

Time interval is from   -2.412 sec. to   46.340 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.31968     ( -0.192098   0.194197 )
Norm@50keV  : 2.26932E-03    ( -0.000248355   0.000248345 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          56.59 using 59 PHA bins.
# Reduced chi-squared =         0.9927 for     57 degrees of freedom 
# Null hypothesis probability =   4.905735e-01
 
Photon flux (15-150 keV)    in 48.75 sec: 0.271745 ( -0.031202  0.031312 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.08819e-06 ( -1.29108e-07  1.29861e-07 ) ergs/cm2

Cutoff power-law model

Time interval is from   -2.412 sec. to   46.340 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.07456     ( -0.413792   0.804491 )
Epeak [keV] : 205.256      ( -205.256 -205.256 )
Norm@50keV  : 2.96149E-03    ( -0.00296149   0.0038992 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          56.24 using 59 PHA bins.
# Reduced chi-squared =          1.004 for     56 degrees of freedom 
# Null hypothesis probability =   4.659514e-01
 
Photon flux (15-150 keV)    in 48.75 sec: 0.268725 ( -0.032407  0.032437 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.07363e-06 ( -1.37418e-07  1.36227e-07 ) ergs/cm2

1-s peak spectrum fit

Power-law model

Time interval is from    1.080 sec. to    2.080 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.874749     ( -0.358749   0.40037 )
Norm@50keV  : 8.59723E-03    ( -0.00194592   0.00186596 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          48.68 using 59 PHA bins.
# Reduced chi-squared =         0.8540 for     57 degrees of freedom 
# Null hypothesis probability =   7.755983e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.986685 ( -0.215248  0.218005 ) ph/cm2/s
Energy fluence (15-150 keV)             : 9.74541e-08 ( -1.99812e-08  2.00194e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from    1.080 sec. to    2.080 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.755674     (       )
Epeak [keV] : 661.796      (   )
Norm@50keV  : 9.60015E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          48.66 using 59 PHA bins.
# Reduced chi-squared =         0.8689 for     56 degrees of freedom 
# Null hypothesis probability =   7.462793e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.981720 ( -0.222551  0.21341 ) ph/cm2/s
Energy fluence (15-150 keV)             : 9.72098e-08 ( -2.03658e-08  2.00097e-08 ) ergs/cm2

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 44.62 sec.
Hardness ratio (energy fluence ratio) = 1.60250712167

S(15-50 keV) vs. S(50-150 keV) plot

S(15-50 keV)  = 3.64215e-07
S(50-150 keV) = 7.239712e-07

The dash-dotted line and the dashed line traces the fluences calculated from the Band function with Epeak = 15 and 150 keV, respectively. Both lines assume a canonical values of alpha = -1 and beta = -2.5.

Mask shadow pattern

IMX = -9.677236238125366E-01, IMY = 7.687974215051663E-02

Spacecraft aspect plot

Bright source in the pre-burst/pre-slew/post-slew images

Pre-burst image of 15-350 keV band

Time interval of the image:
-239.520000 -2.412000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
326.0796  38.4163   14.9  40.3  122.6   0.4302   0.8    7.1	Cyg X-2                       
348.8065  70.5562    2.3  42.7  175.3   1.3574   5.1 ------	UNKNOWN

Pre-slew background subtracted image of 15-350 keV band

Time interval of the image:
-2.412000 40.580600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
326.1203  38.3166  366.3  40.3  122.4   0.0072   0.0    2.4	Cyg X-2                       
 13.9694 -24.0290    1.9  54.4    8.1   1.9473   6.1 ------	UNKNOWN                       
  6.7093  74.3092    0.8  44.2 -175.5   1.6181  14.3 ------	UNKNOWN

Post-slew image of 15-350 keV band

Time interval of the image:
112.780600 962.558100
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
308.0989  40.9990    3.2  42.4   50.4   4.7274   3.6    2.8	Cyg X-3                       
326.1288  38.3109    6.9  40.6   29.1   1.2617   1.7    2.1	Cyg X-2                       
342.7919  20.4865    2.1  55.2    5.1   9.1988   5.5 ------	UNKNOWN                       
 48.6065  41.5047    3.8  37.9  -77.0   3.5960   3.1 ------	UNKNOWN                       
 32.0787  28.8220    3.5  47.2  -53.2   7.5407   3.3 ------	UNKNOWN

Analysis Summary

Notes:

Image

Pre-slew 15.0-350.0 keV image (Event data)

Light Curves

Full-time range; 1 s binning

Other quick-look light curves:

64 ms binning (zoomed) 16 ms binning (zoomed) 8 ms binning (zoomed) 2 ms binning (zoomed) SN=5 or 10 s binning (full-time range) Raw light curve

Spectra

Notes:

Time averaged spectrum fit using the average DRM

Power-law model

Cutoff power-law model

1-s peak spectrum fit

Power-law model

Cutoff power-law model

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

S(15-50 keV) vs. S(50-150 keV) plot

Mask shadow pattern

Spacecraft aspect plot

Bright source in the pre-burst/pre-slew/post-slew images

Pre-burst image of 15-350 keV band

Pre-slew background subtracted image of 15-350 keV band

Post-slew image of 15-350 keV band

64 ms binning (zoomed)
16 ms binning (zoomed)
8 ms binning (zoomed)
2 ms binning (zoomed)
SN=5 or 10 s binning (full-time range)
Raw light curve